1. Field of the Invention
The present invention relates to a process for producing acrolein which comprises catalytic oxidization of propylene in the vapor phase with a gas containing oxygen and steam, in the presence of an oxidizing catalyst which comprises molybdenum, cobalt, iron, bismuth, and tin or, besides tin, by adding one or more elements selected from a group consisting of aluminum, nickel, tungsten, chromium, indium and niobium.
2. Description of the Prior Art
Similar catalysts are cited in Japanese Patent Publication No. 6245/69; Mo - Co / Ni - Fe - Bi and Mo - Co / Ni - Fe - Bi - P. The inventors, after detailed investigation, have found that a catalyst produced by adding tin and, optionally, one or more elements selected from a group consisting of aluminum, nickel, tungsten, chromium, indium and niobium gives a much improved catalyst. For example, in comparison with the catalyst cited in Japanese Patent Publication No. 6245/69, the space time yield of acrolein is increased by more than 100 percent under the same conditions of reaction. This is illustrated by comparison in the examples.